Copolymers of alpha-acetamino-acrylates



we ght. soluble in water.

Patented Feb. 8, 1949 COPOLYMERS F ALPHA-ACETAMINO- ACRYLATES Eliaslsaacs and Herbert Gndgeon, Blackley,.

Manchester, England, assignors to Imperial Chemical Industries Limited,a corporation of Great Britain No Drawing- Application November 15,1945, Se-

rial No. 628,998. In Great Britain November 3 Claims. 1

This invention relates to new polymeric substances and more particularlyit relates to new polymeric substances derived from esters ofa-acetaminoacryllc acid.

According to the invention we manufacture new polymeric substances bycausing esters of a-acetaminoacrylic acid to polymerise alone ortogether with other polymerisable unsaturated substances.

Esters of a-acetaminoacrylic acid may be made by the commonesterification processes from a-acetaminoacrylic acid which itself isobtainable as described by Bergmann and Grafe' (Zeitschrift fiirphysiologische Chemie, 1930, vol. 187, page 187) by the action of aceticacid on aux-diacetaminopropionic acid which results from the interactionof pyruvic acid and acetamide. Suitable esters for use in the process ofthe invention include for example methyl a-acetaminoacrylate, ethyla-acetaminoacrylate and propyl a-acetaminoacrylate.

The polymerisation process of the invention may be carried out accordingto known techniques for the polymerisation of polymerisable unsaturatedsubstances. Thus the polymerisation may be carried out in mass or insolution or in emulsion or dispersion in suitable solvents, for examplein water or ethanol.

Catalysts may be used in the process, to effect polymerisation atgreater speed, but they are not essential. Thus for example suitablecata lysts include oxygen-yielding catalysts, for example benzoylperoxide and ammonium persulphate.

If desired the speed of polymerisation may be still further activatedwhen the polymerisation is conducted in aqueous medium by the presencein addition to an oxygen-yielding catalyst, of a compound capable oftaking up molecular oxygen, especially an oxidisable sulph'oxy compound.for example anoxidisable salt of an oxy-acid of sulphur. for examplesodium sulphite.

As suitable polymerisable unsaturated substances which may be caused' topolymerise alon with the ester of a-acetaminoacrylic acid there may bementioned for example acrylonitrile, methyl methacrylate and styrene.

The polymeric substances obtained accordin to the process of theinvention are clear, hard and colourless resins. In cases where nosecond component is used in the polymerisation the products are. exceptwhen of very high molecular These aqueous solutions are useful asthickening agents and stabllisers for natural and synthetic latices.

. Example 1 Methyl a-acetamino acrylate is heated at 100 C. during 3hours and a clear, colourless,

hard, water-soluble resin is obtained in theoretical yield.

Example 2 Methyl a-acetamino acrylate (10 parts) and benzoyl peroxide(0.1 part) are heated at 100 C. during 3 hours. Ten parts of a clear,colourless resin similar to that of Example 1 are obtained.

Example 3 Methyl a-acetamino acrylate (10 parts) is dissolved in partsof water containing,0.5 part of benzoyl peroxide and the solution isheated at C. during 3 hours. A viscous solution of polymeric methyl'a-acetamino acrylate is obtained.

Example 4 Methyl a-acetamino acrylate (1 part) and acrylonitrile (19parts) are dissolved in distilled water parts) from which air has beenremoved by boiling. Ammonium persulphate (1' part) and sodium sulphite(0.5 part) are added to the solution and the mixture is heated to 30 C.and so maintained during 16 hours while a slow stream of nitrogen ispassed through the containing vessel. A colourless precipitate ofinterpolym'er is formed which is filtered ofi', washed and dried. It isinsoluble in water and in most organic solvents but dissolves readily indimethylformamide.

We claim:

1. A process which comprises heating a solution comprising 1 part byweight of methyl a-acetamino acrylate, 19 parts of acrylonitrile,

3 4 2. A copolymer consisting of 5% by weight or methyl a-acetaminoaorylate and 95% acrylo- REFERENCES CITED ml The following referencesare of record in the 3. A copolymer consisting of 5% by weight of me Ofthis Patent: an alkyl acetamino acrylate from the group con- 5 UNITEDSTATES PATENTS sisting of methyl a-acetammoacrylate, ethyla-acetaminoacrylate and propyl a-acetamino- Number Name Date acrylatewith 95% by weight of an alpha ethylenic 2,211,152 Nicodemus 13. 19 0compound from the group consisting of acrylonitrile, methylmethylmethacrylate, and styrene.

ELIAS ISAACS. HERBERT GUDGEON.

